Athearn blue box

[Lester Perry]

I installed a digitrax decoder in Athearn blue box. Using the kit they have I don't have the papers in front of me, I think it is AT something. I did it exactly as the directions said. It barely moves. This locomotive runs great in DC. It has been fine tuned in the gears etc. Is this a normal problem?

[Chuck]

You probably need to adjust your CV's -- start with your starting voltage. Go online and download the Digitrax manual for your decoder. It will show which cvs need to be adjusted for starting voltage, mid range and high range. You should be able to finely tune your loco to run like a Swiss watch with a little patience. I was able to make my 40 year-old Athearn GP7 run like a proto 2000. Best of luck!
Chuck

[Lester Perry]

Thanks I have been messing wit cv"s but can.t get it.

[torikoos]

Don't give up. I had similar issues with a Tsunami decoder but it is possible to get it to move. First off though, give your engine a good service, clean and relubricate the gears, drive trains, wheel and motor bushings, and clean the motor commutator of all the carbon dust with a clean and dry Q-tip. Then start again.
Download the Digitrax manuals if you haven't already, and have a look if there are more sophisticated motor CV's to set up rather than just start mid and other voltages. A Tsunami has CV's for (technical bit) Proportional, Integrator, and Derivative (PID) controls. Additionally, you can change the sample rate (the amount of times per second the decoder checks the motor responses) between 31 and 2 milliseconds. These factors had a big impact on how my loco runs. It does take time, but check it out if it's possible with your decoder. It is worth it. If it doesn't , don't , but consider if it's worth to re-motor/re-power your loco with a new motor etc. (A-line makes great kits for Athearn). I did this for one of mine, and boy it's worth it!

Oh a common mistake, is the motor well Insulated from the frame? (athearn motors need to be insulated, no more direct contact with the frame, and wires run from the contact strips to the decoder). Particularly the little copper strip at the bottom is sometimes forgotten... you have probably done this, but it's worth mentioning, as it's very easy to overlook. :-)

good luck , Koos.

PS: The link to the full Digitrax decoder manual is here: <!-- m --><a class="postlink" href="http://www.digitrax.com/ftp/Decoder_Manual.pdf">http://www.digitrax.com/ftp/Decoder_Manual.pdf</a><!-- m -->
It is more comprehensive than the one shipped with your decoder I think, it describes a lot of functions, and not all will be applicable to yours perhaps. Check the manual of your decoder to find out which CV's it supports, and then check this decoder manual from this link, to find how to set it up. Hope that helps.

[rrinker]

Something else that can cause erratic operation - the AT harness uses the base of the headlight bracket as the connection to the chassis side of the electrical pickup. On many Blue Box locos, those are riveted rather loosely to the frame and do not make the best electrical pickup points. Fine wire sodlered to the metal plate on the truck (the rivet, actually is easier to solder) is the best option for most reliable pickup - that way both sides of the track power are connected to the decoder with wires. A second alternative would be to drill a hole in the frame and tap it, and install a brass screw. The wire that used to go to the headlight post, with the connector on it, remove the connector and solder the wire to the head of the brass screw.

--Randy

[Steamtrains]

Les....What I've done with the few diesels I have is to ignore the start-up voltage (CV3) and just leave it at it's default value. Nowadays diesels start at such a low voltage that you don't need any "kick". I concentrate on CV5 - high top speed, and CV6 - midrange speed. The most critical CV here is CV6, since it'll affect your low speed as well. Try the following:

1. Do a reset to default values. Set CV8 to a value of 08. This will also reset the loco number to 03. I just leave it at that 'till I'm finished messing with the other two CV's.
2. Set CV5 to determine your engine's top speed (so it doesn't run at hyper-warp speed at the top throttle setting). This will fall at around 150-175 +/-, depending on how fast you like to see your locos run.
3. Set CV6 somewhere around its mid-range value (125/130 +/-).

Now give it a try. It should run nicely. Mess around with the value of CV6 to the point where there's a nice smooth transition from low speed to medium. Once you have that set up to your liking, you can set the values of CV's 3 (accelerating momentum), and CV4 (decelerating momentum).
That's all it takes to get a nicely running diesel. Don't forget to set your engine number to whatever you use before putting it back to work.
All of this supposes that you have no electrical issues as mentioned above. Luckily I haven't had to deal with this.

Hope this helps...

[Lester Perry]

Problem solved. Does Digitrax have a warranty?

[woodone]

HUMMM- this does not sound good?? Does Digitraxx have a warranty ? Did you find the problem or did the decoder go bad?
If you found what was the problem, could you share?

[Lester Perry]

Well....I reset the decoder by going to CV8 and entering 8. It ran great for about 2 feet. At that time it stopped.After trying everything I could think of ,I removed the decoder and plugged it into a tester. It wouldn't make any lights come on.

[woodone]

That was my fear when you asked about the warranty.
Sorry to hear that you are haveing problems. The good new is that Digitraxx has a good warranty. Pack it up and ship it back to them.
BTW there is a service warrnty form to fill out and you should have (a copy) your invoice to prove when you bought it.
That being said, hope the new decoder will make you unit run well.
Make sure you get the motor isulated from the frame.

[rrinker]

Make sure you get the motor isulated from the frame.

I'm going to guess this is where you went wrong, the motor wasn;t totally isolated. The AT harness clips get rid of the stock lower clip's tab that sticks out to make contact with the frame, but you still need to fill up the space under the motor with a layer of electrical tape so there's no chance for the motor, tab, or the solder point on the AT harness tab from contacting the frame. Plain clear tape won't do it, just the motion of putting the motor back in place will cut right through it.
Also check the motor, a motor with a damaged winding might run but that partially shorted winding will make a high current pulse every rotation of the motor which can fry the decoder as well.

--Randy

[woodone]

That would be my guess too Randy. The motor was shorted to the frame on the lower motor contact.
To make sure I get this lower contact insulated , I remove the lower clip on the motor and straighten out the spring part of the clip and put a small spot of solder on it. Then I also put some Kapton tape on the frame and clip.

[rrinker]

Another trick if rolling your own instead of paying for the harness is to swap the clips - the top clip doesn't have the protrusion tha tthe lower one does. Of course it can be tricky - the only things holding the motor together are those clips.

--Randy

[deckroid]

One of the DCC Gurus at my club takes a lot of older engines and chips them. He starts by getting down to the frame then dipping it in some liquid latex for putting new handles on hand tools. That way he is sure not to cause shorts. The down side is one of my F3s has a blue underbelly that is visible.

[woodone]

One of the DCC Gurus at my club takes a lot of older engines and chips them. He starts by getting down to the frame then dipping it in some liquid latex for putting new handles on hand tools. That way he is sure not to cause shorts. The down side is one of my F3s has a blue underbelly that is visible.

Well I guess this will work, but seems like a little over kill. The tape between the two will do the job just fine. And you will not have a colored frame to deal with.